This invention relates to improvements in an air conditioner for a vehicle, capable of providing sufficient hot air even with a long air passage from a heater core to a heater diffuser, so that a driver or passenger of a vehicle can get cool air around his head and hot air around his legs.
The present inventors heretofore have developed an improved an air conditioner, as disclosed in the structure shown in U.S. patent application Ser. No. 597924, and also have developed an experimental model for an air conditioner for a vehicle as shown in FIGS. 5 and 6, (which was designed and performance tested for an experiment in our laboratory not open for public).
The model comprises a heater core for heating air, the air being blown from upstream of the heater core and discharged downstream of the heater core, an air passage arranged in parallel with the heater core, a first damper arranged upstream of the heater core and the air passage and being rotatable for controlling the amount of air passing through the heater core and the amount of air passing through the air passage in accordance with the rotational angle thereof, a first chamber (A) arranged downstream of the heater core and the air passage for mixing the heated air discharged from the heater core and non-heated air passed through the air passage to produce mixed air having suitable temperature (not too cold, not too hot), a second chamber (B) provided a downstream of the first chamber (A) for distributing the mixed air to a ventilation diffuser formed at an instrument panel, so that a passenger can get the mixed air around his head, and a third chamber (C) provided a downstream of the second chamber (B) and having at least one heater diffuser for diffusing the mixed air.
This, however, increases the length of the air passage from the air inlet to the heater and defroster chamber (C), thereby resulting in an increase in the resistance. Thus, the temperature of air from both the heater diffuser and defroster outlet is decreased or rather cool. Further, hot air and cold air are so completely mixed due to the long air passage, that it is hard to obtain the cool air suitable for diffusing from ventilation outlets (E) (F) (G) (connected to a ventilation diffuser formed at the instrument panel by a ventilation duct), and the hot air suitable for diffusing from heater diffuser (H) and defroster outlet (I) (connecting to defroster diffuser formed in the top portion of the instrument panel by a defroster duct) when the device is in the bilevel mode.